Media Perspective: Picking off Emap is crucial challenge for gun-toting Global.(Global Radio S.A's acquisition of EMAP PLC radio division)

It's been a tough week for Prince Philip. Following reports of a health scare, the 86-year-old then had to endure newspaper allegations that he drove to church having neglected to fasten his seatbelt and criticism from protest groups after he was pictured taking 'pot shots' at game birds while at Sandringham.

Yet even a tooled-up Prince Philip has nothing on what's been going on down at Global Radio UK recently. The mortality rate for its management has been alarmingly high since June, when Global acquired Chrysalis Radio for pounds 170 million. The new management team (chaired by the former ITV boss Charles Allen, and led by its chief executive, Ashley Tabor, and the Fame Academy judge and executive director Richard Park) has seemingly been loading cartridges ever since.

But while some believe that they have been indiscriminate in their actions, there has been a clear logic to what has been happening at Global. The heads of each major brand (including Heart and Galaxy) have moved on, making for a leaner structure, which suits Global's needs as a private investment vehicle and also allows Park (who is as close to radio royalty as you can get) to have the room he needs to operate. And it has had the sense to retain Don Thomson, the veteran sales chief at Chrysalis, since promoted to chief operating officer.

The changes smack of a clearing of the decks ahead of a possible acquisition of ...